Breaker and distributor head



Sept. 1, 1936. v w THOMAS 2,052,951

BREAKER AND DISTRIBUTOR HEAD Filed Nov. 15, 1954 2 Sheets-Sheet 1 @ggj 25 5 Sept. 1, 1936. v w THOMAS 2,052,951

BREAKER AND DISTRIBUTOR HEAD Filed Nov. 15, 1934 2 Sheets-Sheet 2 ELI/67321643 v I l v %6652 fl w KWJME Patented Sept. 1, 1936 UNITED STATES PATENT QFFICE Edward A. Harrington, trustee, Waukcgan,

Application November 15, 1934, Serial No. 753,160

1 Claim.

My present invention relates to the provision of a new and improved breaker and distributor head for ignition systems for internal combustion engines, and has for its object the provision of instrumentalities in a breaker and distributor head which are caused to function by change in engine speeds for advancing and retarding the spark and for altering the action between the cam and the breaker so that the time during which the primary circuit is opened and closed will remain substantially the same at different engine speeds.

I have attained the above object by means of the structure and arrangement disclosed in the accompanying drawings, in which Fig. 1 is a top plan of a breaker head with the distributor cap removed.

Fig. 2 is a vertical elevation and section on line 22 of Fig. 1.

Fig. 3 is a plan of the breaker casing with the distributor cap and breaker plate removed.

Fig. 4 is a central vertical section on line 4-4 of Fig. 1, the breaker arm and contact and condenser being omitted for clearness.

Similar reference characters refer to similar parts throughout the respective views.

The stem 5 of the breaker head is centrally bored for the passage of and to form a journal for the spindle '5. Preferably cast integrally with the top of the stem 5 is the casing 1. The casing l is de-centered with respect to the stem 5. The axis of the shaft or spindle 6 is indicated in Figs. 1 and 3 by the reference character X, while the center axis of the casing l is indicated in the same figures by the reference character Y. Adjacent the top of the casing l are provided annular grooves forming the shoulders 8 and 9. The breaker plate I 6 rests and rotates upon the shoulder 8 and has an aperture l l in its center of sufficient extent to permit the breaker plate to be rotated about the portion of the spindle or shaft 6 which projects therethrough. The top of the spindle 6 which extends into and above the compartment in the casing I is slightly reduced, and secured upon the shoulder provided by this reduction by means of a nut I2 is a worm wheel l3. Above the breaker plate H] the spindle or shaft 6 is again reduced, and seating upon the shoulder thus provided is the cam 14 and an upstanding head I5, which is adapted to receive the distributor rotor (not shown). Any suitable means 'may be employed for securing the cam I4 and head 15 to the shaft 6 and I have illustrated an expanding screw [6 for this purpose, which cooperates with the bored and split upper end of the spindle or shaft. This is not an unusual construction, and I have merely shown the expanding screw [6 thereof. The above described construction can be most clearly seen in Fig. 4.

Referring now more particularly to Fig. 1 it will be seen that fixed to the breaker plate I!) and 5 extending upwardly therefrom is a post I! carrying an insulating bushing l8 upon which is mounted a breaker arm l9. Intermediate of its length the breaker arm I9 is provided with a striker or rubbing block 2!] for engagement with the points of thecam M. A bracket 2! is also fixed to and insulated from the breaker plate l0 and secured tothe bracket 25 is one end of a spring 22, the other end whereof is secured to the breaker arm I 9 by means of the screw 23, which also serves to secure the striker or rubbing block thereto In automobile ignition systems it is usual to ground one terminal of the battery, and I have shown a conductor 24 from the battery terminal which is not grounded, leading up through a suitable aperture in the breaker plate [0, and secured to the bracket 25 and in electrical connection with the spring held thereby. I have also shown a conductor 25 leading from one side of the condenser 25 to the bracket 2!. Upon the outer or unattached end of the breaker arm 19 is the movable contact 2i, and secured to an adjustable bracket 29 is the adjustable fixed contact 28 which co-operates with the movable contact 21. The construction, purpose and manner of adjustment of the bracket 29, and also the means herein described for securing uniform electrical operation at divers speeds, were first disclosed by me in application for patent which has been assigned Serial No. 744,386.

The breaker casing l is cast with a hollow development 30, the axis of which is parallel with a tangent to the Worm wheel l3, and opposite the development 30 in the casing l is provided an integral block 3! which is bored to provide a journal for the reduced end of a shaft 32, the opposite end whereof is journaled in a bore in the outer end of the development 30. A screw plug 33 is provided in this bore with a ball 34 for adjusting the shaft 32 in its respective journals.

Fixed to the shaft 32 is a worm gear 35 which meshes with the worm wheel 13. Also fixed to the shaft 32 is a collar 36, and slidably mounted upon the shaft 32 is a collar 37, the hub of which is extended and provided with an annular slot 38. Extended between the peripheries of collars 36 and 31 are a plurality of thin, flexible spring straps 39, secured to the centers of which straps 55 the chamber in the casing I is a stud 4| which is centrally bored for the receipt of a. pin 42 which constitutes the fulcrum of a curved lever arm 43, in one end of which lever arm is fixed a pin 44 which extends into the annular channel 38 of the collar 31. The opposite end of the lever arm 33 isprovided with an elongated slot through which projects a pin 45 fixed to and extending downwardly from the breaker plate [0.

As will be seen by reference to the co-pe-nding application heretofore referred to the rotation of the plate I about the center Y will carry the striker or rubbing block 20 nearer to or farther from the axis X of the shaft or spindle 6 and cam l4, and that by changing the above noted relation the portions of the revolution of the cam, during which the primary circuit is closed and opened, are also changed. That is, when the apparatus is in retarded spark position and the engine is idling and the cam rotating at a relatively slow speed the portion of the cam engaging the'striker or rubbing block 20 is of less extent than when the spark is advanced and the engine or shaft or spindle 6 is rotating more rapidly. The breaker plate is held rotatably upon its shoulder 8 by the heads of the screws 46 and the apparatus is set so that when the engine is idling or going at its slowest speed and the flexible straps 39 are most nearly straight, the rubbing block 20 is at the proper distance from the center X to give the desired current through the primary circuit. As the speed increases the weights 40 are carried outwardly by centrifugal force, which causes the flexing of the straps 39 and the drawing of the collar 31 toward the collar 36. The pin 44, working in the groove 38,

are weights 40. Extending from the bottom of swings the lever arm 43 upon its fulcrum 42 and rotates the breaker plate ID by moving the pin 45, which secures, at the same time, the advancement of the spark and the shortening of the time during which the primary circuit is closed. Upon a reduction of speed of the engine the flexible spring straps 39 will straighten out and the above described operation will be reversed.

By means of suitable measuring devices it will be found that this device will secure the advancement and retarding of the spark uniformly with the change of engine speeds and that the current flowing in the primary circuit will remain substantially constant at all engine speeds.

Having described my invention what I claim is new and desire to secure by Letters Patent is:

A breaker for ignition systems for internal combustion engines comprising a shaft, a cam mounted upon said shaft, a breaker plate mounted for movement about said shaft upon an axis eccentric to the axis of said shaft, a breaker arm mounted upon said breaker plate in co-operative relation with said cam, a fixed contact mounted upon said breaker plate in co-operative relation with said breaker arm, a worm wheel mounted upon said shaft, a shaft mounted with its axis at right angles to the axis of the shaft carrying said worm wheel, a worm gear mounted on said last mentioned shaft in co-operative relation with said worm wheel, a collar fixed upon said last mentioned shaft, a collar slidably mounted upon said last mentioned shaft, a plurality of flexible spring straps connecting said collars, weights mounted intermediate the ends of said straps and a linkage between said movable collar and said breaker plate.

VICTOR W. THOMAS. 

